The term “adjusting element” in the present case is to be understood in broad terms. It encompasses, for example, a tailgate, a trunk lid, an engine hood, a side door, a luggage compartment flap, a lifting roof, or the like of a motor vehicle. The field of application of the motorized adjustment of a tailgate of a motor vehicle is given precedence hereinafter. This is not to be understood as limiting.
During the motorized actuation of tailgates, or the like, the use of spindle drives is becoming increasingly important. The known spindle drive (DE 10 2008 062 391 A1), on which the invention is based, is provided with a drive motor with a spindle-spindle nut gear arranged downstream for producing a drive force along a geometric spindle axis, wherein the drive force is transferred via two connectors on the end face. The spindle drive has an internal housing receiving the drive motor and an external housing which run inside one another in a telescopic manner during the motorized adjustment. In this case, at least one part of the internal housing or the external housing is designed from a plastics material in order to ensure a reduction in weight and to enable latching connections to be produced in a simple manner.
A further known spindle drive (DE 20 2005 000 559 U1) also reveals the use of plastics materials for the housing of the spindle drive. By the use of plastics materials, it is necessary in this case to produce the internal housing or the external housing, for example, from half-shells made of plastics material.
The aforementioned use of plastics materials when producing the internal housing and/or the external housing of spindle drives not only provides advantages with regard to weight and construction but also with regard to the resulting costs. Optimally, however, with regard to the structural design of the spindle drive, the mechanical properties thereof should not be inferior to a spindle drive with a metal housing, in particular with regard to the resulting rigidity.